HORN-R

HORN-R is an active satellite operated by Japan, launched on 2026-06-12 from TNSTA on the VEP-5 launch. As a relatively recent addition to the catalogue, its orbital elements are well-characterised. It orbits in Low Earth Orbit (LEO) at altitudes between 521 km and 548 km with an inclination of 97.7°. It travels at approximately 27,351 km/h (7.60 km/s), completing one full orbit every 95 minutes — that’s roughly 15.11 orbits per day. Its near-polar, sun-synchronous orbit means it passes over any given point on Earth at approximately the same local solar time, ideal for consistent Earth observation lighting conditions. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~3–10 years. Orbital Radar tracks HORN-R in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

HORN-R orbits at an average altitude of 535 km in a sun-synchronous orbit (SSO), a specialised subset of LEO where the orbital plane precesses to maintain a constant angle relative to the Sun. This provides consistent lighting conditions on every pass — essential for Earth observation, weather monitoring and environmental science. Within ±50 km of HORN-R’s average altitude, there are currently 2,534 active payloads and 304 tracked debris or rocket body fragments — notable neighbours include STARLINK-1184, STARLINK-1276, STARLINK-1451. This makes it one of the more crowded altitude bands, containing roughly 14.2% of all active satellites. With an inclination of 97.7°, HORN-R passes over latitudes between 97.7°N and 97.7°S, providing near-global coverage including the polar regions. Polar and near-polar orbits are used for reconnaissance, weather monitoring and Earth-observation missions that need to image every part of the planet. Japan operates approximately 200 active satellites in total, of which 54 share a similar altitude band with HORN-R.